counter-screen

https://doi.org/10.1351/goldbook.14124
Screen in which test samples are assessed against a target for unwanted activity.
Note: This target may or may not be structurally or functionally related to the intended target.
Source:
PAC, 2011, 83, 1129. (Glossary of terms used in biomolecular screening (IUPAC Recommendations 2011)) on page 1136 [Terms] [Paper]